The holy book of the Sikh religion is the Guru Granth Sahib. Originally, the religion relied on the teaching of living gurus. The 10th guru, Gobind Singh, declared that he would have no living successor, and this collection of teachings would become the ultimate guru for the Sikh.
As the Guru is considered a holy teacher, the book is shown reverence in Sikh services. It is typically placed on a throne, and the congregation cover their heads and remove their shoes while in its presence. It is carried upon the head and never by those with unwashed hands. It is also considered a transgression for a Sikh to turn his back on the book.